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H. B. CHESS, i -S'HEARING MACHINE. y No. 294,966. Patented Mar. 11,1884.

fl J' Aa 5 Al1 il h tion that the feet of the clamps keep below Unire@STATES PATENT Grimes.

HARVEY B. CHESS, OF PITTSBURG, PENNSYLVANIA.

SHEARING- MACHINE.

SPECIFICATION forming part of Letters Patent No. 294,966, dated March11, 1884.

' Application inea November 2,1883. (No model.)

.To @ZZ whom it may concern: v

Be it known that I, HARVEY B. OHnss, of Pittsburg, in the county ofAllegheny and State of Pennsylvania, have invented a new and usefulImprovement in Shears for Cutting Sheet Metal, 'of which the followingis a full, clear, and exact description, reference being had to' theaccompanying drawings, making a part of this specification, in which-Figure 1 represents a longitudinal vertical section of a pair of shearswith my improvements attached. Eig. 2 is a front elevation of theclamping device. Fig. 3 are details to be referred to.

My present invention relates, particularly, to means for clamping andsupporting the metal plates while being cut, and it consists in thecombination of devices hereinafter explained and claimed.

To enable others skilled in the art to make and use my invention, I willproceed to describe the exact manner in which I have carried it out.

Vhile shearing sheet metal it is quite essential to clamp down theportion from which the strip is to be cut. I accomplish this by means ofthe arms A, which are pivoted in the rear of the machine at A', andwhich are extended over the shaft B and to the front in a single piece.On the front end of the arm I attach the pressers` or clamps C, as shownin Fig. 2, which are raised by the means of cams D on the shaft B. Thedownward movement of the clamps is brought about by the adjustablesprings E, attached to the arm A by the rod F and thumb-screws j. Ineach downward stroke of the cutting-knife G the clamps C move downslightly in advance of the knife, and, reaching the material first,clamp it down firmly with the spring-pressure, which may be regulated bythe thumb-screw f. On the return or upward movement of the knife theseclamps also travel upward, but in such relathe edge of the upper knife,which facilitates the entering of the sheet or plate when buckled or outof true plane, as it prevents the possibility of the plate catching orimpinging on the edge of the knife. The clamps C are so swiveled orcentrally attached to the arm A in relation to the point of contact withthe plate that their final movement in clamping the plate is inward ortoward the gages H, thus holding the metal against the gages properlyfor cutting. Vhen particularlyT soft metal is being acted on by suchshears, the lack of support and the contact with the descending knifecauses the piece or strip' to be bent downward at the front edge. Theshear 7 is always used, and this giving way or bending downwardcommences at the first moment of the contact with the knife, and, as itcontinues during or throughout the shear cut, the result is theproduction of a spiral strip frequently of great distortion. 6 5

To prevent this and toaid in securing a squarebar, N, extending acrossand over them all.

These ngers are thus kept from rising above the common plane on whichthe plate enters the machine, while they are supported in an upwarddirection by the springs Ol and vertical rods O, and adjusted by thethumbscrews l?.

rIhe action is as follows: The metal is entered at the opening betweenthe knives as far as the gages H will permit. The knife in its descentcommences to cut off the strip, but each finger in succession does itsshare in sus taining (by means of its spring-support) each portion ofthe strip being cut off, and when the severing has been completed thelingers are all drawn backward by the arms on the rock-shaftsufficiently far to allow the strip to drop down andout of the machine.rIhe clearing of the strip from the fingers is accomplished by the gagesH holding the strip in place during the backward movement ofthejrlngers. The strip having dropped, the cam, rock-shaft, v and armsmove the fingers again to their forward position, where they constitutea mova- Ioo ble table for the support of the entering|` sheet.

able spring` O, in combination with the knife Fig. 3 shows the elt'eetof the ent on the strip G and gages II, substantially as and for thewith my improvements attached.

It is evident that the clamps C may be atpurpose set forth. 15

2. In shears for Cutting sheet metal, the

taehed verticallyT to more with a knife rising knives G G and gages II,in Combination and falling,` vertically.

with the clamps C and fingers I, all Construct Having thus described myinvention, what I ed to operate substantially as and for the purclaim tobe new, and desire to secure by Letters Iatent, is-

l. In shears for cutting` sheet metal, the n- `gers I, with suitablemechanism for operating the same, the adjustable stop N, and alljustlpose set forth.

HARVEY B. CHESS. `fitnesses:

WM. N. lllsrox, THOMAS J. ROGERS.

